Improvement in adjustable watch-keys



J. s, BIRCH.

Watch Key.

Patented May 1o, 1870'.

- No.A 102,753;

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Ny PETERS. PNOTO "[HCGRAPMER, WASHINGTON. B C.

drilled States @met (tilt-ire.

JOHN S. BIRCH, OF NEW YORK, N. Y'.

Lam-8 Patent No, 102,753, lated Mayflo, 1ero.

IMPROVEMENT IN ADJUSTABLE WATCH-KEYS.

The Schedule referred to in these Letters Patent and making part of the same.

ing fetch-Keys; and I. do hereby declare that the followingjs a full, clear, and exact description thereof,-

Whchxwill enable others skilled in the art to make and use the same, reference being. had to the accompanying,drawingpf'orming part of this specification, in

which- Figure 1 is a side view -of my improved watch-key. vFigure 2 is an enlarged longitudinal section of the same.

Similar letters of reference indicate -corresponding parts.

My present invention is an improvement on the keys for which I have obtainedA Letters Patent bearing date, respectively, November 12, 1867, and April 13, 1869; and

Thev improvement contemplates producing a key that shall be simpler in construction, less liable to be` come injured or broken, and may be more easily and quickly operated, as well as more economically manufactured. j

vA represents a short tube, in which the jaws B slide, and which may be provided with ring projections or collars for convenience in holding and operating the instrument.

B are the jaws, the inner surface of the outer ends of which arenotched upon their inner sides, to receive and grasp the arbor ot' the. watch or other object to beheld.

The jaws B get gradually thinner from' the shoulders of their outer ends to their necks, or their enlargement at their inner ends 5 but their outer surfaces are so formed as to be always the arc of a circle in,4 theircross-'section', wherever saidcross-section be made.

The jaws B may be made in two pieces, secured to 'each' other by-a-1rivet passing transversely through their inner ends@ The thinner part, of the jaws B is made so thin, and is `so formed, that. its .elasticity will always hold the outer surfaces pf Ysaid jaws `pressed against the inner 'surface oftheitubc A, so that the jaws will open au- 'tomaticallyras they are forced ont of the said tube A,

and will close as they are drawn back into said tube. j

In case the jaws B are hinged at their inner ends, a small spring should be placed between them of sufcient strength to force them apart as they move out of the tube A.

C is a stay-pin, which passes transversely through.

the jaws B, and through a slot in the tube A.

Knobs, heads, or slides may be formed -npon or. attached to the ends ,of the pin O, to enable it to be used for pushing the jaws B out of the tube A, and drawing theminto snid tube; the main object of the pin O being to resist the turning pressure upon the jaws when the key is being used.

Having thus described my invention,

What I claim asne\v, and desire to secure by Letters Patent, is

The improved watch-key, consisting of the case A, provided with'opposite longitudinal slots, in which the stay-pin O slides, the same passingtransversely through the slot in the spring-jaws B B, (riveted together at 'their inner ends, and made semicircular in cross-section,) all arranged as specified, whereby the pin supports the strain when the key is being-used.

The above specification of my yinvention ysigned by me this 25th day of June, 1869.

` J. S. BIRCH.

Witnesses:

FRANK BLOCKLEY, JAMES T. GRAHAM. 

